I have a sneaking suspicion that the reason we haven’t found any evidence for advanced civilizations elsewhere in the universe is that they are consistently short-lived – a few thousand years, out of the billions of years that stars have existed. So the chance of stumbling across one is really small. And, by the same logic, if we ever do encounter a signal from a distant planet, the possibility that its senders will still be surviving by the time the signal reaches us, is tiny too. Other advanced civilizations, if they occur, may be short-lived aberrations in the timeline of the universe since they quickly self-destruct.
Imagine that in a few years time we erase our civilization with nuclear weapons or climate change: the time frame within which we will have been able to send out radio signals announcing our presence to any listeners will have been just a few decades. If the same is true of other civilizations, the chance of receiving a similar radio signal from another civilization is very unlikely, even if they were similarly inclined to try to make contact.